This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A049723 #9 Aug 07 2021 01:13:07
%S A049723 1,4,4,9,6,9,18,13,13,18,29,22,15,22,29,46,33,26,26,33,46,63,50,39,35,
%T A049723 39,50,63,82,67,54,46,46,54,67,82,107,88,71,60,56,60,71,88,107,136,
%U A049723 115,96,79,75,75,79,96,115,136,169,140,119,100
%N A049723 Array T read by diagonals; T(i,j)=number of lattice points (x,y) in closed right half-plane and circle with radius (0,0)-to-(i,j).
%C A049723 Specifically, -i<=x<=i, 0<=y<=j, x^2 + y^2 <= i^2 + j^2.
%e A049723 Diagonals (each starting on row 1): {1}; {4,4}; {9,6,9}; ...
%Y A049723 T(n, 0)=A036695(n).
%K A049723 nonn,tabl
%O A049723 0,2
%A A049723 _Clark Kimberling_